EP3450047B1 - A method of producing a ceramic core for investment casting - Google Patents
A method of producing a ceramic core for investment casting Download PDFInfo
- Publication number
- EP3450047B1 EP3450047B1 EP18188645.8A EP18188645A EP3450047B1 EP 3450047 B1 EP3450047 B1 EP 3450047B1 EP 18188645 A EP18188645 A EP 18188645A EP 3450047 B1 EP3450047 B1 EP 3450047B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- slurry
- core
- carbon fibers
- ceramic
- ceramic core
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000000919 ceramic Substances 0.000 title claims description 53
- 238000000034 method Methods 0.000 title claims description 40
- 238000005495 investment casting Methods 0.000 title claims description 13
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 78
- 239000002002 slurry Substances 0.000 claims description 33
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 31
- 239000004917 carbon fiber Substances 0.000 claims description 31
- 238000010304 firing Methods 0.000 claims description 23
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 12
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 claims description 12
- 229910052863 mullite Inorganic materials 0.000 claims description 12
- 239000011230 binding agent Substances 0.000 claims description 9
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical class [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 claims description 7
- 239000002245 particle Substances 0.000 claims description 5
- 229910052710 silicon Inorganic materials 0.000 claims description 5
- 239000010703 silicon Substances 0.000 claims description 5
- 229910052593 corundum Inorganic materials 0.000 claims description 3
- 229910001845 yogo sapphire Inorganic materials 0.000 claims description 3
- 239000011162 core material Substances 0.000 description 93
- 239000000377 silicon dioxide Substances 0.000 description 35
- 229910052751 metal Inorganic materials 0.000 description 16
- 239000002184 metal Substances 0.000 description 16
- 238000005266 casting Methods 0.000 description 15
- 238000006243 chemical reaction Methods 0.000 description 15
- 229910045601 alloy Inorganic materials 0.000 description 9
- 239000000956 alloy Substances 0.000 description 9
- 238000001816 cooling Methods 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 8
- 150000002739 metals Chemical class 0.000 description 7
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 238000001746 injection moulding Methods 0.000 description 4
- 238000002386 leaching Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000011148 porous material Substances 0.000 description 4
- 239000000835 fiber Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000000465 moulding Methods 0.000 description 3
- 230000009257 reactivity Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 229910052727 yttrium Inorganic materials 0.000 description 3
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 3
- 238000009472 formulation Methods 0.000 description 2
- 238000010297 mechanical methods and process Methods 0.000 description 2
- 229910001092 metal group alloy Inorganic materials 0.000 description 2
- 238000001000 micrograph Methods 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000009877 rendering Methods 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 238000004626 scanning electron microscopy Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 229910000601 superalloy Inorganic materials 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000002144 chemical decomposition reaction Methods 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 230000005226 mechanical processes and functions Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000005058 metal casting Methods 0.000 description 1
- 239000002114 nanocomposite Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/10—Cores; Manufacture or installation of cores
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D53/00—Making other particular articles
- B21D53/78—Making other particular articles propeller blades; turbine blades
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C1/00—Compositions of refractory mould or core materials; Grain structures thereof; Chemical or physical features in the formation or manufacture of moulds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C7/00—Patterns; Manufacture thereof so far as not provided for in other classes
- B22C7/06—Core boxes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/02—Sand moulds or like moulds for shaped castings
- B22C9/04—Use of lost patterns
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D19/00—Casting in, on, or around objects which form part of the product
- B22D19/0072—Casting in, on, or around objects which form part of the product for making objects with integrated channels
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/013—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics containing carbon
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/16—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on silicates other than clay
- C04B35/18—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on silicates other than clay rich in aluminium oxide
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/62605—Treating the starting powders individually or as mixtures
- C04B35/6269—Curing of mixtures
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
- C04B35/6303—Inorganic additives
- C04B35/6316—Binders based on silicon compounds
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/71—Ceramic products containing macroscopic reinforcing agents
- C04B35/78—Ceramic products containing macroscopic reinforcing agents containing non-metallic materials
- C04B35/80—Fibres, filaments, whiskers, platelets, or the like
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
- C04B38/06—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by burning-out added substances by burning natural expanding materials or by sublimating or melting out added substances
- C04B38/063—Preparing or treating the raw materials individually or as batches
- C04B38/0635—Compounding ingredients
- C04B38/0645—Burnable, meltable, sublimable materials
- C04B38/065—Burnable, meltable, sublimable materials characterised by physical aspects, e.g. shape, size or porosity
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/12—Blades
- F01D5/14—Form or construction
- F01D5/18—Hollow blades, i.e. blades with cooling or heating channels or cavities; Heating, heat-insulating or cooling means on blades
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/22—Moulds for peculiarly-shaped castings
- B22C9/24—Moulds for peculiarly-shaped castings for hollow articles
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/48—Organic compounds becoming part of a ceramic after heat treatment, e.g. carbonising phenol resins
- C04B2235/483—Si-containing organic compounds, e.g. silicone resins, (poly)silanes, (poly)siloxanes or (poly)silazanes
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
- C04B2235/52—Constituents or additives characterised by their shapes
- C04B2235/5208—Fibers
- C04B2235/5264—Fibers characterised by the diameter of the fibers
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
- C04B2235/52—Constituents or additives characterised by their shapes
- C04B2235/5296—Constituents or additives characterised by their shapes with a defined aspect ratio, e.g. indicating sphericity
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
- C04B2235/602—Making the green bodies or pre-forms by moulding
- C04B2235/6027—Slip casting
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6567—Treatment time
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/66—Specific sintering techniques, e.g. centrifugal sintering
- C04B2235/661—Multi-step sintering
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/80—Phases present in the sintered or melt-cast ceramic products other than the main phase
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2230/00—Manufacture
- F05D2230/20—Manufacture essentially without removing material
- F05D2230/21—Manufacture essentially without removing material by casting
Definitions
- the present disclosure generally relates to investment casting components and methods for making them.
- the present disclosure relates to ceramic cores used to produce internal channels inside turbine blades in the investment casting process.
- Investment casting often utilizes cores to produce internal channels inside cast metals.
- a molten metal or alloy is poured into a mold containing a core. After the metal solidifies, the core is removed to leave behind the internal channels.
- the architecture of the internal channels is determined by the features of the core.
- Cores formed through injection molding and other conventional processes can produce simple hollow channel architectures.
- more complex channel geometries are desirable due to their improved blade performance, where air is blown through the hollow channels of the cast blade for cooling.
- Improved blade cooling performance can take the form of reduced cooling air flow, which allows for increased utilization of air for combustion and thus increases engine thrust.
- Higher blade cooling performance allows for an increase in combustor operating temperature and improved thermodynamic efficiency, resulting in better specific fuel consumption, while still maintaining turbine blade component temperatures within an acceptable range for durability.
- Especially useful channel geometries for turbine blade cooling circuits are described in, for instance, U.S. Pat. No. 5,660,524 , U.S. Pat. No.
- the individual molded sections are then assembled after molding and firing, with a concomitant reduction in core yield for precision investment casting, due to the loss of registry between the parts.
- the multi-piece process is also much more expensive due to the capital cost of multiple mold tools, the hand work needed for core finishing and assembly, and the further reduction in net casting yield, due to the poorer dimensional tolerances and mechanical stability during casting of the multi-piece core assembly.
- One way to produce cores with both simple and complex channel architectures is with disposable core dies (DCD) described in, for instance, U.S. Pat. No. 7,487,819 .
- the core is formed by injecting a slurry containing ceramic particles and an organic binder into a disposable core die. The slurry is then cured and then fired to produce a solidified ceramic core.
- the disposable core die can be removed before, during or after the core firing process, for instance by a chemical, thermal or mechanical process.
- Ceramic core materials used in the investment casting industry are often made predominately of silica (SiO 2 ).
- Silica is a commonly used core material in investment casting because of its low coefficient of thermal expansion, high-temperature dimensional stability, and its ease of removal from the casting.
- Articles made by investment casting are cast metal or metal alloys. In some instances, this metal may react with the conventional silica-based ceramic core. Therefore, the use of silica-containing core materials for casting of reactive metals is known to be problematic, as silica may react with certain metals during the casting process.
- Yttrium addition to an alloy is one approach for improving the oxidation resistance of nickel-based superalloys at the service temperature of turbine airfoils.
- yttrium can react with silica during casting, leading to depletion of the yttrium in the alloy and introducing components into the alloy that debit the mechanical properties and the ability to further process turbine airfoils, resulting major limitations in using silica cores for the casting of these (reactive) nickel-based superalloys.
- Alumina and yttria materials have been used in casting to reduce or eliminate this reactivity problem.
- Alumina for instance, is less reactive than silica.
- alumina is harder to process than silica materials with respect to higher temperatures required for processing. This introduces problems with dimensional tolerances because of the higher coefficient of thermal expansion and inherent large creep rate relative to silica.
- Alumina cores can also require more extreme leaching conditions for their removal after casting because of their lower solubility and/or leach rates. These constraints apply equally to ceramic cores formed through conventional methods such as injection molding, as well as those formed by the DCD process.
- US 8 286 689 B1 discloses a method of forming a porous ceramic body.
- US 2010/048374 A1 discloses a system and method for establishing proper quantities of components in the initial mixture to be used in the fabrication of a porous ceramic substrate.
- US 2004/029706 A1 discloses ceramic nanocomposite comprising a nanostructured carbon component inside a ceramic host.
- US 2017/144216 A1 discloses a method for producing a ceramic core for investment casting of reactive metal.
- the method includes injecting a slurry into a disposable die (100), the slurry comprising ceramic particles, binders, and carbon fibers (201), characterized in that the slurry is an Al 2 O 3 -siloxane based slurry with the added carbon fibers (201) aligned in the direction of the slurry flow, and further comprises a first firing step that converts silicon in the siloxane based slurry to amorphous silica, wherein the first firing step temperature is between 250°C and 750°C and the first firing time is between 10 and 20 hours, and a second firing step that removes the carbon fibers (201) and converts the amorphous silica and excess Al 2 O 3 to mullite, wherein the second firing step temperature is between 1050°C and 1700°C and the second firing time is between one hour and 24
- the ceramic core can define an internal surface of a turbine blade.
- the slurry can include carbon fibers in a concentration not exceeding 20 wt% of the slurry.
- the carbon fibers can have an average diameter of 200 microns or less.
- the carbon fibers can have an average diameter of 100 microns or less.
- the carbon fibers can have an aspect ratio of greater than 10:1 up to 100:1.
- the first firing step can burn off the disposable die.
- Ceramic cores are used to produce internal channels inside turbine blades in the investment casting process. Blades made of Y-bearing metals or alloys improve engine service temperatures by 50°C. The use of the silica-based cores for casting of these reactive metals or alloys poses melting issues, as silica reacts with certain metals during the casting process.
- US 2017/0144216 assigned to General Electric Company discloses a ceramic core comprising alumina particles and siloxane binders; non-reactive cores that reduce or eliminate the reactivity problem.
- cores based on non-reactive Al 2 O 3 /mullite formulation need to possess significantly more porosity so that the core may be readily removed from the internal of a blade, and yet structurally strong enough to survive the core manufacturing process.
- the present invention provides a method to produce core bodies with improved mechanical strength and increased porosity by introducing an optimum amount of carbon fibers to the non-reactive core fabrication process.
- the non-reactive cores include siloxane binders, fugitive species, and ceramic powders.
- the siloxane binders and fugitive species upon thermal decomposition, create porosity in the final core body. Both pre-existing and newly formed ceramic phases give strength to a core body to maintain dimensional integrity. Further improvements on core and casting quality call for higher mechanical strength.
- a porosity of more than 40 vol% with an interconnected pore structure helps to increase the leaching efficiency during the core removal process.
- the present invention provides Al 2 O 3 - siloxane based slurry with added carbon fiber for making ceramic cores using the DCD process.
- the carbon fibers strengthen the core body during the manufacturing process and introduce additional porosity in the finished core for the ease of core leaching.
- the present invention provides ceramic cores with unique features that include open porosity, and increased mechanical strength at the same time.
- Traditional metal dies or DCD may be used for this process, as may injection molding or any other type of conventional molding.
- the present invention provides a ceramic core which has compatibility with the DCD process, is substantially non-reactive during casting, and allows for the production of structures with intricate internal shapes while possessing the compatibility with the alloy sought for articles formed by investment casting.
- the slurry is transferred into a disposable core die. Once the slurry is transferred into the die, the slurry may be cured to form a solidified article, that is, for example, a green body.
- the temperature for curing is between 25°C and 110°C. In other embodiments, the temperature for curing is between 40°C and 80°C. In still other embodiments, the temperature for curing is between 50°C and 70°C. In yet other embodiments, the temperature for curing is between 55°C and 65°C. In some embodiments, the time for curing is between 1 hour and 24 hours. Any time and temperature combination that will cure the slurry to a green body is acceptable.
- the curing step may be approximately two hours at 50°C. As another non-limiting example, the curing step may be approximately 24 hours at 35°C. In another non-limiting example, the curing may be for 6 hours at 55°C.
- the cured product includes a semi-hardened ceramic material including fibers encased in the DCD die.
- the conversion occurs in a two-step firing process.
- the first low-temperature firing step converts the silicon in the siloxane binder to amorphous silica while not significantly degrading carbon fibers in the core body.
- This "low fire" step burns off the die.
- the first step is performed for between 10 and 20 hours. In some embodiments, the first step is performed for between 12 and 18 hours. In other embodiments, the first step is performed for approximately 16 hours.
- the first firing step temperature is between 250°C and 750°C. In some embodiments the first temperature is between 350°C and 650°C. In other embodiments, the first temperature is between 400°C and 600°C, or the first temperature is between 450°C and 550°C.
- the core then undergoes further heat treatment (i.e., a high-temperature firing).
- a high-temperature firing i.e., a high-temperature firing
- the amorphous silica in combination with the excess alumina is converted to mullite and the carbon fibers are totally burnt out, resulting in a desired microstructure with a predominantly elongated pore structure.
- the firing step temperature for this conversion is between 1050°C and 1700°C. In some embodiments the temperature is between 1150°C and 1650°C, or between 1200°C and 1650°C. In some embodiments, the temperature for this conversion is between 1400°C and 1650°C, or the temperature for this step is between 1450°C and 1650°C.
- the temperature for this step is between 1500°C and 1650°C, or the temperature for this step is between 1500°C and 1600°C. In some embodiments, the temperature for this conversion is between 1550°C and 1650°C, or the temperature for this conversion is between 1575°C and 1625°C. In other embodiments, the temperature for this conversion is between 1400°C and 1600°C, or the temperature for this conversion is between 1450°C and 1600°C. In yet other embodiments, the temperature for this conversion is between 1550°C and 1600°C.
- the time utilized for this conversion is between one hour and 24 hours. In some embodiments, the time utilized for this conversion is between one hour and 12 hours. In some embodiments, the time utilized for this conversion is between one hour and 6 hours. In some embodiments, the time utilized for this conversion is one hour. Any time and temperature combination that will maximize the conversion of the amorphous silica-containing core to a mullite-containing ceramic core as described herein is acceptable.
- the slurry is cured to form a green body.
- the second heating event is the low fire step described above.
- the third heating event is the conversion of silica in the presence of excess alumina to mullite.
- the curing and firing steps may be accomplished in a single furnace in a single run. In other embodiments, the firing steps may be accomplished in a single furnace in a single run.
- the formed ceramic core comprises mullite, alumina, and free silica.
- Free silica may be present in the ceramic core, but much of this silica is encapsulated by mullite, rendering it "hidden” (or “substantially non-reactive") from the metal, not available for reaction with metal alloy on a continuous basis, functionally inert, and compatible with casting of reactive alloys.
- the ceramic core contains up to 11 wt % free silica, or the ceramic core contains up to 10 wt % free silica, or the ceramic core contains up to 8 wt % free silica.
- the ceramic core contains up to 6 wt % free silica, or the ceramic core contains up to 3 wt % free silica. In some embodiments, the ceramic core contains up to 1 wt % free silica. In some embodiments, the ceramic core contains between 0.1 wt % and 10 wt % free silica. In other embodiments, the ceramic core contains between 0.1 wt % and 5 wt % free silica, or between 0.1 wt % and 6 wt % free silica. In still other embodiments, the ceramic core contains between 1 wt % and 10 wt % free silica.
- the ceramic core contains between 1 wt % and 5 wt % free silica, or between 0.1 wt % and 3 wt % free silica. In yet other embodiments, the ceramic core contains between 1 wt % and 3 wt % free silica, or the ceramic core contains between 0.5 wt % and 1 wt % free silica. In some embodiments, the ceramic core contains between 2 wt % and 8 wt % free silica. In still other embodiments, the ceramic core contains between 3 wt % and 6 wt % free silica. In other embodiments, the ceramic core contains between 0.1 wt % and 1 wt % free silica.
- the thermally-converted slurry may also include other materials, such as silica, other Al 2 O 3 --SiO 2 polyforms that are below the XRD detection limit.
- the remaining free silica may be encapsulated by the formed mullite, rendering it non- or minimally-reactive for subsequent casting steps.
- the present invention incorporates carbon fiber into the core formulations for producing ceramic cores.
- FIG. 1 is an illustration of a thin wall disposable core die 100 that is used to manufacture a turbine airfoil.
- a slurry comprising ceramic particles, a binder, and carbon fibers according to an embodiment of the present invention may be directionally added into the interstices and channels of the thin wall disposable core die 100.
- the slurry is then subjected to curing to form a cured ceramic core.
- the disposable core die 100 is removed to leave behind the cured ceramic core as shown in FIG. 2.
- FIG. 2 is an illustration of the cured ceramic core after being fired to form a solidified ceramic core 200.
- the carbon fibers 201 align in the direction of slurry flow as shown, for example, in FIG. 2 .
- FIG. 3 shows a scanning electron microscopy (SEM) micrograph of a longitudinal view on a polished surface showing carbon fibers orienting predominantly along the flow of slurry.
- the sample was fired up to 500°C.
- carbon fibers orient predominantly along the direction of slow flow. This carbon fiber alignment is critical in reducing cracks during the subsequent plastic die removing phase. Carbon fibers remain in the core body after thermal decomposition of plastic die around 500°C (first fire), reinforcing the core body because carbon fibers do not oxide until at a higher temperature.
- FIG. 4 shows a SEM micrograph of a transverse view on a polished surface showing extensive cracks ( ⁇ 10 ⁇ m in width) leading to the part interior. The sample was fired up to 1650°C.
- FIG.5 is a XRD spectrum on an as-fired surface of a core fired up to 1650°C in air. It demonstrates that the remaining phases are 3;2 mullite and ⁇ -Al2O2.
- FIG. 6 illustrates an increase in the Modulus of Rupture at room temperature (RT MOR) with the addition of carbon fiber. The 4 point bend results are from 5" long test bars fired up to 1650°C. As illustrated in FIG. 6 , the unique microstructure due to transient carbon fiber reinforcement improves mechanical strength to help cores maintain structure integrity while achieving higher porosity.
- the disposable core die may be removed using chemical, thermal, mechanical methods or a combination comprising at least one of the foregoing methods. Examples of such methods include chemical dissolution, chemical degradation or a combination comprising at least one of the foregoing methods of removing.
- the core may be leached from the cast metal turbine blade using a caustic agent that dissolves the ceramic core while not affecting the cast metal part.
Description
- The present disclosure generally relates to investment casting components and methods for making them. In particular, the present disclosure relates to ceramic cores used to produce internal channels inside turbine blades in the investment casting process.
- Investment casting often utilizes cores to produce internal channels inside cast metals. A molten metal or alloy is poured into a mold containing a core. After the metal solidifies, the core is removed to leave behind the internal channels. The architecture of the internal channels is determined by the features of the core.
- Cores formed through injection molding and other conventional processes can produce simple hollow channel architectures. However in some applications, such as cast blades for gas turbines, more complex channel geometries are desirable due to their improved blade performance, where air is blown through the hollow channels of the cast blade for cooling. Improved blade cooling performance can take the form of reduced cooling air flow, which allows for increased utilization of air for combustion and thus increases engine thrust. Higher blade cooling performance allows for an increase in combustor operating temperature and improved thermodynamic efficiency, resulting in better specific fuel consumption, while still maintaining turbine blade component temperatures within an acceptable range for durability. Especially useful channel geometries for turbine blade cooling circuits are described in, for instance,
U.S. Pat. No. 5,660,524 ,U.S. Pat. No. 6,036,441 ,U.S. Pat. No. 6,168,381 ,U.S. Pat. No. 6,595,748 andU.S. Pat. No. 6,832,889 . A major limitation to commercial implementation of these representative cooling circuits in turbine blades is the inability to produce the necessary ceramic cores as single piece articles by conventional molding techniques. Examination of the cooling circuit geometries of interest shows that there exists no single parting line allowing the construction of separable mold halves to enable removal of a molded part without destroying part of the formed structure. Accordingly, production of cores to produce such sophisticated cooling circuits requires elaborate multi-step processes where the geometry is broken up into several moldable sections, each with its own separate mold tooling. The individual molded sections are then assembled after molding and firing, with a concomitant reduction in core yield for precision investment casting, due to the loss of registry between the parts. The multi-piece process is also much more expensive due to the capital cost of multiple mold tools, the hand work needed for core finishing and assembly, and the further reduction in net casting yield, due to the poorer dimensional tolerances and mechanical stability during casting of the multi-piece core assembly. - One way to produce cores with both simple and complex channel architectures is with disposable core dies (DCD) described in, for instance,
U.S. Pat. No. 7,487,819 . The core is formed by injecting a slurry containing ceramic particles and an organic binder into a disposable core die. The slurry is then cured and then fired to produce a solidified ceramic core. The disposable core die can be removed before, during or after the core firing process, for instance by a chemical, thermal or mechanical process. - Ceramic core materials used in the investment casting industry are often made predominately of silica (SiO2). Silica is a commonly used core material in investment casting because of its low coefficient of thermal expansion, high-temperature dimensional stability, and its ease of removal from the casting. Articles made by investment casting are cast metal or metal alloys. In some instances, this metal may react with the conventional silica-based ceramic core. Therefore, the use of silica-containing core materials for casting of reactive metals is known to be problematic, as silica may react with certain metals during the casting process.
- Yttrium addition to an alloy is one approach for improving the oxidation resistance of nickel-based superalloys at the service temperature of turbine airfoils. However, yttrium can react with silica during casting, leading to depletion of the yttrium in the alloy and introducing components into the alloy that debit the mechanical properties and the ability to further process turbine airfoils, resulting major limitations in using silica cores for the casting of these (reactive) nickel-based superalloys.
- Alumina and yttria materials have been used in casting to reduce or eliminate this reactivity problem. Alumina, for instance, is less reactive than silica. However, alumina is harder to process than silica materials with respect to higher temperatures required for processing. This introduces problems with dimensional tolerances because of the higher coefficient of thermal expansion and inherent large creep rate relative to silica. Alumina cores can also require more extreme leaching conditions for their removal after casting because of their lower solubility and/or leach rates. These constraints apply equally to ceramic cores formed through conventional methods such as injection molding, as well as those formed by the DCD process.
-
US 8 286 689 B1 discloses a method of forming a porous ceramic body. -
US 2010/048374 A1 discloses a system and method for establishing proper quantities of components in the initial mixture to be used in the fabrication of a porous ceramic substrate. -
US 2004/029706 A1 discloses ceramic nanocomposite comprising a nanostructured carbon component inside a ceramic host. -
US 2017/144216 A1 discloses a method for producing a ceramic core for investment casting of reactive metal. - Therefore, there is a need for a low reactivity material system compatible with DCD processing for producing cores that can generate cast articles with complex internal channel architectures made using reactive metals and alloys.
- The following presents a simplified summary of one or more aspects of the present disclosure in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
- The foregoing and/or other aspects of the present invention may be achieved by a method of producing a ceramic core for investment casting in accordance with the appended Claims. In one aspect, the method includes injecting a slurry into a disposable die (100), the slurry comprising ceramic particles, binders, and carbon fibers (201), characterized in that the slurry is an Al2O3-siloxane based slurry with the added carbon fibers (201) aligned in the direction of the slurry flow, and further comprises
a first firing step that converts silicon in the siloxane based slurry to amorphous silica, wherein the first firing step temperature is between 250°C and 750°C and the first firing time is between 10 and 20 hours, and a second firing step that removes the carbon fibers (201) and converts the amorphous silica and excess Al2O3 to mullite, wherein the second firing step temperature is between 1050°C and 1700°C and the second firing time is between one hour and 24 hours. In exemplary embodiments, at least a portion of the ceramic core can define an internal surface of a turbine blade. In further exemplary embodiments, the slurry can include carbon fibers in a concentration not exceeding 20 wt% of the slurry. In further exemplary embodiments, the carbon fibers can have an average diameter of 200 microns or less. In further exemplary embodiments, the carbon fibers can have an average diameter of 100 microns or less. In further embodiments, the carbon fibers can have an aspect ratio of greater than 10:1 up to 100:1. In further exemplary embodiments, the first firing step can burn off the disposable die. - Other features and aspects may be apparent from the following detailed description, the drawings, and the claims.
-
-
FIG. 1 is an illustration of a thin wall disposable core die. -
FIG. 2 is an illustration of a solidified ceramic core showing fibers oriented predominantly along the flow of the slurry, according to an embodiment of the present invention. -
FIG. 3 shows a scanning electron microscopy (SEM) micrograph of a longitudinal view on a polished surface showing fibers orienting predominantly along the flow of slurry. -
FIG. 4 shows a SEM micrograph of a transverse view on a polished surface showing extensive cracks (∼10µm in width) leading to the part interior. -
Figure 5 XRD Spectrum of an as-fired Surface of a core fired up to 1650°C -
Figure 6 illustrates an increase in the Modulus of Rupture at room temperature (RT MOR) with the addition of carbon fiber. - The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known components are shown in block diagram form in order to avoid obscuring such concepts.
- Ceramic cores are used to produce internal channels inside turbine blades in the investment casting process. Blades made of Y-bearing metals or alloys improve engine service temperatures by 50°C. The use of the silica-based cores for casting of these reactive metals or alloys poses melting issues, as silica reacts with certain metals during the casting process.
US 2017/0144216 assigned to General Electric Company discloses a ceramic core comprising alumina particles and siloxane binders; non-reactive cores that reduce or eliminate the reactivity problem. - Especially, cores based on non-reactive Al2O3/mullite formulation need to possess significantly more porosity so that the core may be readily removed from the internal of a blade, and yet structurally strong enough to survive the core manufacturing process. The present invention provides a method to produce core bodies with improved mechanical strength and increased porosity by introducing an optimum amount of carbon fibers to the non-reactive core fabrication process.
- The non-reactive cores according to an aspect of the invention include siloxane binders, fugitive species, and ceramic powders. The siloxane binders and fugitive species, upon thermal decomposition, create porosity in the final core body. Both pre-existing and newly formed ceramic phases give strength to a core body to maintain dimensional integrity. Further improvements on core and casting quality call for higher mechanical strength. On the other hand, a porosity of more than 40 vol% with an interconnected pore structure helps to increase the leaching efficiency during the core removal process.
- To address the seemingly contradictory requirements, the present invention provides Al2O3- siloxane based slurry with added carbon fiber for making ceramic cores using the DCD process. The carbon fibers strengthen the core body during the manufacturing process and introduce additional porosity in the finished core for the ease of core leaching. Thus, the present invention provides ceramic cores with unique features that include open porosity, and increased mechanical strength at the same time. Traditional metal dies or DCD may be used for this process, as may injection molding or any other type of conventional molding.
- The present invention provides a ceramic core which has compatibility with the DCD process, is substantially non-reactive during casting, and allows for the production of structures with intricate internal shapes while possessing the compatibility with the alloy sought for articles formed by investment casting.
- As mentioned above, slurry is transferred into a disposable core die. Once the slurry is transferred into the die, the slurry may be cured to form a solidified article, that is, for example, a green body. In some embodiments, the temperature for curing is between 25°C and 110°C. In other embodiments, the temperature for curing is between 40°C and 80°C. In still other embodiments, the temperature for curing is between 50°C and 70°C. In yet other embodiments, the temperature for curing is between 55°C and 65°C. In some embodiments, the time for curing is between 1 hour and 24 hours. Any time and temperature combination that will cure the slurry to a green body is acceptable. As a non-limiting example, the curing step may be approximately two hours at 50°C. As another non-limiting example, the curing step may be approximately 24 hours at 35°C. In another non-limiting example, the curing may be for 6 hours at 55°C. The cured product includes a semi-hardened ceramic material including fibers encased in the DCD die.
- The conversion occurs in a two-step firing process. The first low-temperature firing step converts the silicon in the siloxane binder to amorphous silica while not significantly degrading carbon fibers in the core body. This "low fire" step, in some embodiments, burns off the die. The first step is performed for between 10 and 20 hours. In some embodiments, the first step is performed for between 12 and 18 hours. In other embodiments, the first step is performed for approximately 16 hours. The first firing step temperature is between 250°C and 750°C. In some embodiments the first temperature is between 350°C and 650°C. In other embodiments, the first temperature is between 400°C and 600°C, or the first temperature is between 450°C and 550°C.
- The core then undergoes further heat treatment (i.e., a high-temperature firing). In this step, the amorphous silica in combination with the excess alumina is converted to mullite and the carbon fibers are totally burnt out, resulting in a desired microstructure with a predominantly elongated pore structure. The firing step temperature for this conversion is between 1050°C and 1700°C. In some embodiments the temperature is between 1150°C and 1650°C, or between 1200°C and 1650°C. In some embodiments, the temperature for this conversion is between 1400°C and 1650°C, or the temperature for this step is between 1450°C and 1650°C. In still other embodiments, the temperature for this step is between 1500°C and 1650°C, or the temperature for this step is between 1500°C and 1600°C. In some embodiments, the temperature for this conversion is between 1550°C and 1650°C, or the temperature for this conversion is between 1575°C and 1625°C. In other embodiments, the temperature for this conversion is between 1400°C and 1600°C, or the temperature for this conversion is between 1450°C and 1600°C. In yet other embodiments, the temperature for this conversion is between 1550°C and 1600°C. The time utilized for this conversion is between one hour and 24 hours. In some embodiments, the time utilized for this conversion is between one hour and 12 hours. In some embodiments, the time utilized for this conversion is between one hour and 6 hours. In some embodiments, the time utilized for this conversion is one hour. Any time and temperature combination that will maximize the conversion of the amorphous silica-containing core to a mullite-containing ceramic core as described herein is acceptable.
- In some embodiments, there may be three separate heating events used for this procedure. In the first heating event, the slurry is cured to form a green body. The second heating event is the low fire step described above. The third heating event is the conversion of silica in the presence of excess alumina to mullite. In some embodiments, the curing and firing steps may be accomplished in a single furnace in a single run. In other embodiments, the firing steps may be accomplished in a single furnace in a single run.
- The formed ceramic core comprises mullite, alumina, and free silica. Free silica may be present in the ceramic core, but much of this silica is encapsulated by mullite, rendering it "hidden" (or "substantially non-reactive") from the metal, not available for reaction with metal alloy on a continuous basis, functionally inert, and compatible with casting of reactive alloys. There may be some free silica present in the ceramic core that is potentially reactive, but these amounts should be minimal. In some embodiments, the ceramic core contains up to 11 wt % free silica, or the ceramic core contains up to 10 wt % free silica, or the ceramic core contains up to 8 wt % free silica. In some embodiments, the ceramic core contains up to 6 wt % free silica, or the ceramic core contains up to 3 wt % free silica. In some embodiments, the ceramic core contains up to 1 wt % free silica. In some embodiments, the ceramic core contains between 0.1 wt % and 10 wt % free silica. In other embodiments, the ceramic core contains between 0.1 wt % and 5 wt % free silica, or between 0.1 wt % and 6 wt % free silica. In still other embodiments, the ceramic core contains between 1 wt % and 10 wt % free silica. In some embodiments, the ceramic core contains between 1 wt % and 5 wt % free silica, or between 0.1 wt % and 3 wt % free silica. In yet other embodiments, the ceramic core contains between 1 wt % and 3 wt % free silica, or the ceramic core contains between 0.5 wt % and 1 wt % free silica. In some embodiments, the ceramic core contains between 2 wt % and 8 wt % free silica. In still other embodiments, the ceramic core contains between 3 wt % and 6 wt % free silica. In other embodiments, the ceramic core contains between 0.1 wt % and 1 wt % free silica.
- For purposes of this disclosure, the majority of the silicon-containing constituents initially present in the slurry in the form of siloxane binders are converted to the silicon-containing 3:2 mullite phase. However, it is to be understood that, in addition to 3:2 mullite and alumina, the thermally-converted slurry may also include other materials, such as silica, other Al2O3--SiO2 polyforms that are below the XRD detection limit. The remaining free silica may be encapsulated by the formed mullite, rendering it non- or minimally-reactive for subsequent casting steps.
- According to an aspect, the present invention incorporates carbon fiber into the core formulations for producing ceramic cores.
-
FIG. 1 is an illustration of a thin wall disposable core die 100 that is used to manufacture a turbine airfoil. A slurry comprising ceramic particles, a binder, and carbon fibers according to an embodiment of the present invention may be directionally added into the interstices and channels of the thin wall disposable core die 100. The slurry is then subjected to curing to form a cured ceramic core. The disposable core die 100 is removed to leave behind the cured ceramic core as shown inFIG. 2. FIG. 2 is an illustration of the cured ceramic core after being fired to form a solidifiedceramic core 200. Thecarbon fibers 201 align in the direction of slurry flow as shown, for example, inFIG. 2 . -
FIG. 3 shows a scanning electron microscopy (SEM) micrograph of a longitudinal view on a polished surface showing carbon fibers orienting predominantly along the flow of slurry. The sample was fired up to 500°C. According to an embodiment as shown inFIG. 3 , during the slurry injection molding process, carbon fibers orient predominantly along the direction of slow flow. This carbon fiber alignment is critical in reducing cracks during the subsequent plastic die removing phase. Carbon fibers remain in the core body after thermal decomposition of plastic die around 500°C (first fire), reinforcing the core body because carbon fibers do not oxide until at a higher temperature. - During the subsequent second/setter fire up to 1650°C in air, carbon fibers fully oxidize to CO and CO2. These gaseous species evaporate from the cores, creating interconnected pore structure within the cores. The resultant pore structure aids the leaching process in the core removal step.
FIG. 4 shows a SEM micrograph of a transverse view on a polished surface showing extensive cracks (∼10µm in width) leading to the part interior. The sample was fired up to 1650°C. -
FIG.5 is a XRD spectrum on an as-fired surface of a core fired up to 1650°C in air. It demonstrates that the remaining phases are 3;2 mullite and α-Al2O2.FIG. 6 illustrates an increase in the Modulus of Rupture at room temperature (RT MOR) with the addition of carbon fiber. The 4 point bend results are from 5" long test bars fired up to 1650°C. As illustrated inFIG. 6 , the unique microstructure due to transient carbon fiber reinforcement improves mechanical strength to help cores maintain structure integrity while achieving higher porosity. - After metal casting, the disposable core die may be removed using chemical, thermal, mechanical methods or a combination comprising at least one of the foregoing methods. Examples of such methods include chemical dissolution, chemical degradation or a combination comprising at least one of the foregoing methods of removing. In the case of a turbine blade, the core may be leached from the cast metal turbine blade using a caustic agent that dissolves the ceramic core while not affecting the cast metal part.
- This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims. Aspects from the various embodiments described, can be mixed and matched by one of ordinary skill in the art to construct additional embodiments and techniques in accordance with principles of this application.
Claims (7)
- A method of producing a ceramic core including open porosity using a disposable core die process for investment casting, the method comprising at least a step of:
injecting a slurry into a disposable die (100), the slurry comprising ceramic particles, binders, and carbon fibers (201), characterized in that the slurry is an Al2O3-siloxane based slurry with the added carbon fibers (201) aligned in the direction of the slurry flow, the method further comprising:a first firing step that converts silicon in the siloxane based slurry to amorphous silica, wherein the first firing step temperature is between 250°C and 750°C and the first firing time is between 10 and 20 hours, anda second firing step that removes the carbon fibers (201) and converts the amorphous silica and excess Al2O3 to mullite, wherein the second firing step temperature is between 1050°C and 1700°C and the second firing time is between one hour and 24 hours. - The method of claim 1, wherein at least a portion of the ceramic core defines an internal surface of a turbine blade.
- The method of claim 1 or claim 2, wherein the slurry includes carbon fibers (201) in a concentration not exceeding 20 wt% of the slurry.
- The method of any of claims 1-3, wherein the carbon fibers (201) have an average diameter of 200 microns or less.
- The method of any of claims 1-4, wherein the carbon fibers (201) have an average diameter of 100 microns or less.
- The method of any of claims 1-5, wherein the carbon fibers (201) have an aspect ratio of greater than 10:1 up to 100:1.
- The method of any of claims 1-6, wherein the first firing step burns off the disposable die (100).
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US15/689,748 US20190060982A1 (en) | 2017-08-29 | 2017-08-29 | Carbon fibers in ceramic cores for investment casting |
Publications (2)
Publication Number | Publication Date |
---|---|
EP3450047A1 EP3450047A1 (en) | 2019-03-06 |
EP3450047B1 true EP3450047B1 (en) | 2021-03-31 |
Family
ID=63244450
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP18188645.8A Active EP3450047B1 (en) | 2017-08-29 | 2018-08-13 | A method of producing a ceramic core for investment casting |
Country Status (6)
Country | Link |
---|---|
US (2) | US20190060982A1 (en) |
EP (1) | EP3450047B1 (en) |
JP (2) | JP2019076954A (en) |
CN (1) | CN109420735A (en) |
CA (1) | CA3014459C (en) |
SG (1) | SG10201806805PA (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114920572A (en) * | 2022-06-17 | 2022-08-19 | 中国联合重型燃气轮机技术有限公司 | Woven carbon fiber reinforced ceramic core, preparation method thereof and corresponding investment casting method |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170144216A1 (en) * | 2015-11-19 | 2017-05-25 | General Electric Company | Compositions for cores used in investment casting |
Family Cites Families (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS51122910A (en) | 1975-04-19 | 1976-10-27 | Sen Kenkiyuushiyo Goushi | Flexible slat component plate complex body |
JPS5348026A (en) * | 1976-05-25 | 1978-05-01 | Nisshin Steel Co Ltd | Method and apparatus to manupacture core for casting mould |
GB2086780B (en) | 1980-11-12 | 1984-12-12 | Rolls Royce | Core or core part for use in the lost wax casting process |
IL85506A (en) | 1987-02-24 | 1991-09-16 | United Technologies Corp | Ceramic core molding composition |
US5660524A (en) | 1992-07-13 | 1997-08-26 | General Electric Company | Airfoil blade having a serpentine cooling circuit and impingement cooling |
DE69607056T2 (en) * | 1995-05-10 | 2000-11-09 | Toshiba Kawasaki Kk | Fiber reinforced ceramic composite material and method for its production |
US5744173A (en) | 1996-02-27 | 1998-04-28 | Aeroquip Corporation | Mold inserts for injection moldings |
JP3747115B2 (en) * | 1997-05-16 | 2006-02-22 | 株式会社共立 | Die casting core |
US6364000B2 (en) | 1997-09-23 | 2002-04-02 | Howmet Research Corporation | Reinforced ceramic shell mold and method of making same |
FR2785836B1 (en) | 1998-11-12 | 2000-12-15 | Snecma | PROCESS FOR PRODUCING THIN CERAMIC CORES FOR FOUNDRY |
US6036441A (en) | 1998-11-16 | 2000-03-14 | General Electric Company | Series impingement cooled airfoil |
US6168381B1 (en) | 1999-06-29 | 2001-01-02 | General Electric Company | Airfoil isolated leading edge cooling |
US6595748B2 (en) | 2001-08-02 | 2003-07-22 | General Electric Company | Trichannel airfoil leading edge cooling |
US20040029706A1 (en) * | 2002-02-14 | 2004-02-12 | Barrera Enrique V. | Fabrication of reinforced composite material comprising carbon nanotubes, fullerenes, and vapor-grown carbon fibers for thermal barrier materials, structural ceramics, and multifunctional nanocomposite ceramics |
US6832889B1 (en) | 2003-07-09 | 2004-12-21 | General Electric Company | Integrated bridge turbine blade |
US20100048374A1 (en) * | 2005-11-16 | 2010-02-25 | James Jenq Liu | System and Method for Fabricating Ceramic Substrates |
US7487819B2 (en) * | 2006-12-11 | 2009-02-10 | General Electric Company | Disposable thin wall core die, methods of manufacture thereof and articles manufactured therefrom |
JP5348026B2 (en) | 2010-03-08 | 2013-11-20 | 宇部興産株式会社 | Method for producing an asymmetric hollow fiber gas separation membrane |
EP2463043A1 (en) | 2010-12-08 | 2012-06-13 | Siemens Aktiengesellschaft | Ceramic casting mould part with various shrinking factors and casting methods |
US8286689B1 (en) * | 2011-08-30 | 2012-10-16 | United Technologies Corporation | Porous ceramic body and method therfor |
CN102489670B (en) * | 2011-12-13 | 2013-04-03 | 丹阳市精密合金厂有限公司 | Ceramic core for molding of support plate and preparation method thereof |
US20160010471A1 (en) * | 2013-03-11 | 2016-01-14 | General Electric Company | Coating systems and methods therefor |
US9649687B2 (en) * | 2014-06-20 | 2017-05-16 | United Technologies Corporation | Method including fiber reinforced casting article |
CN104399885B (en) * | 2014-10-28 | 2017-01-25 | 沈阳黎明航空发动机(集团)有限责任公司 | Method for increasing permeability of investment cast ceramic shell |
US10507515B2 (en) * | 2014-12-15 | 2019-12-17 | United Technologies Corporation | Ceramic core for component casting |
-
2017
- 2017-08-29 US US15/689,748 patent/US20190060982A1/en not_active Abandoned
-
2018
- 2018-08-10 SG SG10201806805PA patent/SG10201806805PA/en unknown
- 2018-08-13 EP EP18188645.8A patent/EP3450047B1/en active Active
- 2018-08-16 CA CA3014459A patent/CA3014459C/en active Active
- 2018-08-24 JP JP2018156833A patent/JP2019076954A/en active Pending
- 2018-08-28 CN CN201810986208.3A patent/CN109420735A/en active Pending
-
2020
- 2020-12-23 JP JP2020213810A patent/JP7088612B2/en active Active
-
2021
- 2021-01-29 US US17/162,779 patent/US11389861B2/en active Active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170144216A1 (en) * | 2015-11-19 | 2017-05-25 | General Electric Company | Compositions for cores used in investment casting |
Also Published As
Publication number | Publication date |
---|---|
US20190060982A1 (en) | 2019-02-28 |
JP7088612B2 (en) | 2022-06-21 |
SG10201806805PA (en) | 2019-03-28 |
JP2019076954A (en) | 2019-05-23 |
US11389861B2 (en) | 2022-07-19 |
CN109420735A (en) | 2019-03-05 |
CA3014459A1 (en) | 2019-02-28 |
CA3014459C (en) | 2020-09-29 |
JP2021062406A (en) | 2021-04-22 |
EP3450047A1 (en) | 2019-03-06 |
US20210197249A1 (en) | 2021-07-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1600230B1 (en) | System and Method for manufacturing investment casting shells | |
US7946335B2 (en) | Ceramic cores for casting superalloys and refractory metal composites, and related processes | |
US6274078B1 (en) | Method of removing cores from ceramic matrix composite articles | |
US8196640B1 (en) | Self supporting core-in-a-core for casting | |
CN109304424B (en) | Modified silicon oxide powder and preparation method thereof, ceramic core and preparation method thereof | |
EP2564952B1 (en) | Porous ceramic body and method therefor | |
US20120073303A1 (en) | Metal injection molding process and components formed therewith | |
JP2017094397A (en) | Compositions for cores used in investment casting | |
Kim et al. | Single crystal casting of gas turbine blades using superior ceramic core | |
CN108059445A (en) | Calcium oxide-based ceramic-mould that a kind of non-aqueous gel casting quickly manufactures and preparation method thereof | |
US11389861B2 (en) | Carbon fibers in ceramic cores for investment casting | |
KR102075925B1 (en) | Mold coating agents for titanium alloy castings, mold for titanium alloy casings using the same and manufacturing method thereof | |
US4043377A (en) | Method for casting metal alloys | |
KR101763122B1 (en) | Manufacturing method of ceramic core, ceramic core, precision casting method and precision casting products | |
KR20180076355A (en) | Manufacturing method for mold for casting titanium alloy and mold for casting titanium alloy thereof | |
CN106083005A (en) | High porosity easily removes silicon-base ceramic core preparation method | |
US10364189B2 (en) | Methods for forming ceramic cores | |
CN106475520B (en) | Method of manufacturing precision-cast parts for vehicle exhaust systems | |
EP3431206B1 (en) | Apparatus and method for investment casting core manufacture | |
JP2007283382A (en) | Core for casting, core for precision casting, and precision cast product manufactured using the same core for precision casting | |
US6510887B1 (en) | Method for producing casted body having thin portion | |
CN117642239A (en) | Improved casting core for manufacturing hollow metal aerospace parts | |
EP3693098A1 (en) | Investment casting pin and method of using same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20190906 |
|
RBV | Designated contracting states (corrected) |
Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: EXAMINATION IS IN PROGRESS |
|
17Q | First examination report despatched |
Effective date: 20200212 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R079 Ref document number: 602018014633 Country of ref document: DE Free format text: PREVIOUS MAIN CLASS: B22C0001000000 Ipc: B22D0019000000 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: B22D 19/00 20060101AFI20201208BHEP Ipc: C04B 35/18 20060101ALI20201208BHEP Ipc: B22C 1/00 20060101ALI20201208BHEP Ipc: B22C 7/06 20060101ALI20201208BHEP Ipc: B22C 9/10 20060101ALI20201208BHEP Ipc: C04B 35/63 20060101ALI20201208BHEP Ipc: C04B 35/626 20060101ALI20201208BHEP Ipc: B22C 9/24 20060101ALI20201208BHEP Ipc: C04B 38/06 20060101ALI20201208BHEP |
|
INTG | Intention to grant announced |
Effective date: 20201223 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602018014633 Country of ref document: DE Ref country code: AT Ref legal event code: REF Ref document number: 1376376 Country of ref document: AT Kind code of ref document: T Effective date: 20210415 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG9D |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210630 Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210630 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20210331 |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 1376376 Country of ref document: AT Kind code of ref document: T Effective date: 20210331 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210802 Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210731 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602018014633 Country of ref document: DE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: ES Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20220104 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20210831 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210831 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210831 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210731 Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210813 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210813 Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20210831 |
|
P01 | Opt-out of the competence of the unified patent court (upc) registered |
Effective date: 20230515 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: HU Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO Effective date: 20180813 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20230720 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20230720 Year of fee payment: 6 Ref country code: DE Payment date: 20230720 Year of fee payment: 6 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20210331 |